Shakespeare’s silliest comedy–which borrows freely from its source, an equally silly comedy by Plautus–often tempts misguided directors and actors to wallow in bad puns, paper-thin characters, and painfully stupid slapstick scenes. And this open-air production falls into all the traps laid by Shakespeare’s coincidence-laden, totally unbelievable story about the chaotic doings when two pairs of long-separated twins end up in the same town at the same time. Jack Hickey’s staging is packed with annoyingly over-the-top acting, unfunny physical bits, and lovers who don’t seem the least bit interested in each other. Only 2 of the 16 cast members–Katherine Banks and Mercy Oni–create credible, fully realized characters free of the actor’s tricks that make the rest of them grating after only a few minutes. Through 8/22: Thu-Sun 8 PM. Sun 7/17 and 8/7, 4 and 8 PM (4 PM shows preceded by “Family Day” activities beginning 3:15 PM). Oak Park Festival Theatre, Austin Gardens, Forest and Lake, Oak Park, 708-445-4440. $5-$25; dinner packages available.